This invention relates to toothbrushes, and is particularly concerned with the design of a toothbrush especially adapted for use in the modified Bass method and other approved methods for oral hygiene.
In the modified Bass method for brushing the teeth, the brush is placed in the region of the sulcus, that is the joinder line between the tooth and the gum, and moved horizontally so as to dislodge food particles and other foreign particle matter from that region. The toothbrush is then rotated away from the sulcus toward the occlusal surface of the teeth to flick out particles of foreign matter in the area, and to wipe matter outwardly from between the teeth.
If particles are on the side surfaces of the tooth itself, they can readily be reached by the ordinary toothbrush for removal. Plaque accumulates in the sulcus, which in turn causes caries and periodontal disease. Structurally standard types of toothbrushes do not conform well to the anatomy of the teeth and gum, and therefore are difficult to position or introduce gum and tooth damage. Also, they are often too hard, and many are too difficult to use to teach proper brushing.
Toothbrushes of many shapes and designs have been proposed in the prior art in an attempt to remove particles from tooth crevices. Thus, numerous toothbrushes have been disclosed which have various configurations of angled bristles adapted to form a tapered cross section or an outwardly divergent cross section in the body of the brush. Examples of such prior art toothbrushes are shown in the following patents: U.S. Pat. Nos. 560,663; 1,753,290; 2,004,633; 2,097,987; 2,155,245; 2,168,964; 2,429,740; 2,592,099; 2,618,801; 2,807,820; and 4,081,876. These earlier brushes, however, have been designed either with very limited or highly specialized objectives in mind. They have not considered in interrelated fashion the numerous factors which affect efficient brushing action.
When employing the conventional toothbrushes of the prior art for cleaning the teeth, as by the modified Bass technique, frequent abrasions occur on the hard and soft tissues. The sulcus areas are often not cleaned at all because of the inability of such brushes to effectively negotiate the gingival areas and the anatomical grooves of the teeth. Thus, in many instances the brushes are too large, the tufts are angled incorrectly or flare too much, or the surface area of the bristles, together with the stiffness or softness of the bristles, presents an excessively firm or yielding surface. Fewer but larger bristles provide one type of brushing sensation and action, for example, but this can be changed substantially by varying the number of bristles per tuft, the diameter of the individual bristles or the contact surface area of the brushes. Often when employing conventional toothbrushes in the modified Bass method, which should be carefully practiced, the wrong row of tufts are inserted into the sulcus.
There is therefore a need for a toothbrush which is particularly designed for easy and effective use in dislodging and cleaning particular matter from the junction between the gum and the teeth.